<template>
	<view class="uni-numbox">
		<view :class="{ 'uni-numbox--disabled': inputValue <= min || disabled }" class="uni-numbox__minus"
			@click.stop="_calcValue('minus')">－</view>
		<input :disabled="disabled || inputValue <= min" class="uni-numbox__value" type="number" :value="inputValue"
			@input="changeValue" />
		<view :class="{ 'uni-numbox--disabled': inputValue >= max || disabled }" class="uni-numbox__plus"
			@click.stop="_calcValue('plus')">＋</view>
	</view>
</template>
<script>
	export default {
		name: 'UniNumberBox',
		props: {
			value: {
				type: [Number, String],
				default: 1,
			},
			min: {
				type: [Number, String],
				default: 1,
			},
			max: {
				type: [Number, String],
				default: 100,
			},
			step: {
				type: [Number, String],
				default: 1,
			},
			disabled: {
				type: Boolean,
				default: false,
			},
		},
		data() {
			return {
				inputValue: 0,
				timer: null,
			}
		},
		watch: {
			value: {
				handler(value) {
					if (this.inputValue != +value) {
						this.inputValue = +value
					}
				},
				deep: true,
				immediate: true,
			},
			inputValue(newVal, oldVal) {
				this.timer && clearTimeout(this.timer)
				this.timer = setTimeout(() => {
					if (oldVal === 0) return
					if (!newVal) return
					this.$emit('input', newVal)
					this.$emit('change', newVal)
				}, 100)
				// }
			},
		},
		created() {
			this.inputValue = +this.value
		},
		methods: {
			_calcValue(type) {
				if (this.disabled) return
				if (this.max == 0) return this.$message.info('该商品已售馨')
				if (type === 'minus' && this.inputValue == 1) return this.$message.info('不能再少了呦~')
				if (type === 'plus' && +this.max <= +this.inputValue) return this.$message.info('该商品最多能购买' + this.max +
					'件')
				const scale = this._getDecimalScale()
				let value = this.inputValue * scale
				let step = this.step * scale
				if (type === 'minus') {
					value -= step
					if (value < this.min * scale) return
					if (value > this.max * scale) {
						value = this.max * scale
					}
				} else if (type === 'plus') {
					value += step
					if (value > this.max * scale) return
					if (value < this.min * scale) {
						value = this.min * scale
					}
				}
				this.inputValue = String(value / scale)
			},
			_getDecimalScale() {
				let scale = 1
				// 浮点型
				if (~~this.step !== this.step) {
					scale = Math.pow(10, (this.step + '').split('.')[1].length)
				}
				return scale
			},
			changeValue(e) {
				let value = +e.detail.value ? +e.detail.value : this.min
				if (value > +this.max) {
					value = this.max
					this.$message.info('该商品最多能购买' + this.max + '件')
				} else if (value < +this.min) {
					value = this.min
					this.$message.info('不能再少了呦~')
				}
				setTimeout(() => {
					this.inputValue = parseInt(Number(value))
				}, 400)
				return value
			},
		},
	}
</script>
<style>
	.uni-numbox {
		display: inline-flex;
		flex-direction: row;
		justify-content: flex-start;
		height: 46upx;
		position: relative;
	}

	.uni-numbox__minus,
	.uni-numbox__plus {
		margin: 0;
		width: 46upx;
		font-size: 32upx;
		height: 100%;
		line-height: 46upx;
		text-align: center;
		display: inline-flex;
		align-items: center;
		justify-content: center;
		color: #333;
		position: relative;
		font-weight: bold;
		background: #eeeeee;
		padding: 10rpx 20rpx;
	}

	.uni-numbox__value {
		position: relative;
		/* background-color: #f9f9f9; */
		width: 70upx;
		height: 100%;
		text-align: center;
		padding: 0;
		border-radius: 8rpx;
		margin: 0 10rpx;
		/* background: #F7F7F7; */
	}

	.uni-numbox--disabled {
		color: silver;
		/* background: #f9f9f9; */
	}
</style>